I do not like aliased fonts so I deactivated it in the systemsettings. I head wonderful clear fonts for years but since the latest XServer upgrade they are ragged. I had this problem in the beginning, dpkg-reconfigure fontconfig-config helped then but now not any more.

I haven't done a DU for over a week. Are you referring to the update of the x11-common and xserver-xorg packages? In the past (perhpas not on aptosid) libfreetype6 was the culprit as the bytecode interpreter and subpixel hinting were not always enabled. There were pattern issue, which now do not apply.

Like you, I prefer not to use AA fonts below 12pt. So I have AA enabled in the KDE settings and set an exclude range of 0 to 12pt. Can you use this method to get the fonts you want? Or do they still remain "ragged".

Might be time to have a look around at some of the new fonts that are available.

I'm using Droid Sans and I'm quite happy with it. It's a font designed for computer screens (handheld specifically) but it works very well for desktop too.

Here's a clip from apt-get show fonts-droid:

The Droid family of fonts consists of Droid Sans (Regular and Bold),
Droid Sans Mono (Regular) and Droid Serif (Regular, Bold, Italic and
BoldItalic).
.
Each contains extensive character set coverage including
Western Europe, Eastern/Central Europe, Baltic, Cyrillic, Greek and
Turkish support. The Droid Sans regular font also includes support for
Arabic, Simplified and Traditional Chinese, Hebrew, Japanese, Korean and
Thai.
.
Droid was designed by Ascender's Steve Matteson and hinted to provide
optimal quality for screen text.